can i replace SunTour aR II derailer?
10-13-20, 11:17 AM
#1
Newbie
Thread Starter
can i replace SunTour aR II derailer?
Hi,
i just purchased a used FUJI Allegra, The derailleur appears to not function properly(lots of slack ), i am wondering what my options are to replace it.
Any help would be appreciated.
Jim
i just purchased a used FUJI Allegra, The derailleur appears to not function properly(lots of slack ), i am wondering what my options are to replace it.
Any help would be appreciated.
Jim
10-13-20, 12:07 PM
#2
Old fart
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"Lots of slack," as in the cable needs tightening, or something else?
The derailleur can be replaced, but it's not clear to me if the derailleur is actually the problem.
The derailleur can be replaced, but it's not clear to me if the derailleur is actually the problem.
10-13-20, 12:43 PM
#3
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Thread Starter
it doesn't appear to be the cable(i tried pulling all slack out of that). The derailleur doesn't seem to retract(move freely?) properly, which would suck up slack. like there is broken spring inside?.
10-13-20, 12:50 PM
#4
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Overhaul it. Check youtube for how-to vids.
10-13-20, 01:31 PM
#5
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You can test this easily: Disconnect the cable from the derailleur. Then, move the derailleur by hand to the largest sprocket while pedalling and let it go. If it returns to the smallest sprocket on its own the spring is fine
Last edited by alcjphil; 10-13-20 at 01:34 PM.
10-13-20, 01:48 PM
#6
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Thread Starter
the larger spring between the sprocket cage and the derailleur seems very stiff(took it apart via youtube), so if i wanted to replace the derailleur? would any replacement do? or is there a recommendation? this is rather old, i doubt i want to the one.
Thank you
Thank you
10-13-20, 02:09 PM
#7
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Then the question the OP is asking is "would any replacement do?"
The short answer is "no"
Some considerations: Index shifting or non index? Long cage or short? Frame mount using a dropout boss or claw attachment?
But again, it isn't clear to us that the problem is the derailleur. The derailleur is a part of a system that also includes shift levers, cables, cable guides and probably some sort of adjuster(s).
May I suggest that if the new to you bike has shifting problems that it probably has other areas that also need attention before beginning your journey into cycling excellence?
The short answer is "no"
Some considerations: Index shifting or non index? Long cage or short? Frame mount using a dropout boss or claw attachment?
But again, it isn't clear to us that the problem is the derailleur. The derailleur is a part of a system that also includes shift levers, cables, cable guides and probably some sort of adjuster(s).
May I suggest that if the new to you bike has shifting problems that it probably has other areas that also need attention before beginning your journey into cycling excellence?
10-13-20, 02:28 PM
#8
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AR II appears to be a pre index steel bodied derailleur. First I'd try lubing while moving it back & forth as well as cage back forthv using something like PB blaster/Kroil/screwloose to free up stiff joints. Lube the cable anywhere it goes through housing. Freeing up the stiff derailleur is best accomplished with the wheel and chain removed.
VeloBase.com - Component: SunTour aR II
VeloBase.com - Component: SunTour aR II
10-13-20, 06:13 PM
#9
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John
10-13-20, 06:35 PM
#10
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Since the derailleur is pre-index, ‘84/‘85, you are running friction shifting, so you can go with just about anything. But before you run out and buy one, you should consider if you might want to go with a 7 speed wide range freewheel some day, such as a Sunrace MFM300 14-34. The reason I am suggesting a future potential freewheel, is so you buy a rear derailleur that will handle a max cog of 34t. Maybe a long cage SGS Tourney or Acera.
John
John
10-13-20, 06:45 PM
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FYI, if the bike is mid-80’s, you probably have a 6 speed freewheel now, the rear dropout spacing should be 126mm, 4-15/16”. If it is, then you can one day use a 7 speed freewheel. But you don’t need to.
John
John
11-01-20, 09:33 AM
#12
Newbie
Thread Starter
front Crankset
Thank you for your suggestion, it worked great. could you advice me on upgrading the front Crankset from 2 sprocket to 3 sprocket(for big hills), is that possible with this bike
(80's Fuji Allegra)?
Thank you
(80's Fuji Allegra)?
Thank you
11-01-20, 10:38 AM
#13
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This is a little tougher. Not too long ago, there were a lot of older cranks on eBay and flat chainrings were pretty cheap.
It may be possible to install a small enough inner chainring if BCD is 110mm, probably not likely. The distance between adjacent chainring bolts is approximately 2-1/2”. If it is then you should be able to install a 34t on you crank.
If you can’t, it becomes a matter of finding a road triple, bottom bracket, and front derailleur. Probably a Tourney road, or a Claris crank. Sugino makes a triple, but it is pretty expensive.
Make sure you don’t pick up a mtb crank, I’ve done it on a road frame with a mix-n-match BB, but it is not something I’d recommend.
John
It may be possible to install a small enough inner chainring if BCD is 110mm, probably not likely. The distance between adjacent chainring bolts is approximately 2-1/2”. If it is then you should be able to install a 34t on you crank.
If you can’t, it becomes a matter of finding a road triple, bottom bracket, and front derailleur. Probably a Tourney road, or a Claris crank. Sugino makes a triple, but it is pretty expensive.
Make sure you don’t pick up a mtb crank, I’ve done it on a road frame with a mix-n-match BB, but it is not something I’d recommend.
John
